No Contamination Threat in Floodway

EPA finds chemical and pesticide contamination below levels of health concern in Birds Point-New Madrid Floodway.

Published on: Jul 6, 2011

Detailed analysis of the May 24 limited sampling of floodwaters in the Birds Point-New Madrid Floodway in southeast Missouri found contamination at levels typically found in the Mississippi River in nine samples of collected water. The samples are also below levels of health concern for those involved with continuing cleanup activities. Previous results had indicated the presence of E. coli bacteria, however it was detected well below Missouri's official standard for fishing, wading and boating activities.

EPA crews conducted surface water sampling at six locations within the floodway and three outside the floodway to determine if any threats might be present for emergency response workers who could come into contact with the floodwaters.

"Public health and the health of emergency responders are always critical issues in any flood response," said EPA Region 7 Administrator Karl Brooks. "While the levels found were below health concerns, we still recommend the use of appropriate personal protection equipment for the public and workers who may contact floodwater." 

EPA's surface water samples were analyzed for organophosphorus pesticides, triazine herbicides, total metals including aluminum, perchlorate, total petroleum hydrocarbons, gasoline range organics, and TPH-diesel range organics.  

Levels of metals found in surface waters were consistent with those found in the Mississippi River and were below health- based limits. Of the organic compounds analyzed, only perchlorate and two herbicides (atrazine and metolachlor) were actually detected above the detection limits of the instruments used by the laboratory.

Metolachlor was found at three locations, slightly above the detection limit of 0.2 micrograms per liter (ug/L), ranging from 0.21 to 0.26 ug/L. Atrazine was found in all nine samples, and ranged from 0.38 to 1.1 ug/L. Both of these are below EPA's respective drinking water Maximum Contaminant Level or Health Advisory level. These levels are used as conservative health-protective screening values for incidental ingestion of water. The data are also consistent with concentrations found upstream in the Mississippi River throughout the year by the U.S. Geological Survey at their water quality monitoring station in Thebes, Mo.

The primary concern regarding activities in receding floodwaters continues to be the potential presence of bacteria. EPA continues to advise citizens to avoid contact with floodwaters, if possible. Harmful bacteria in the water can cause symptoms such as stomach ache, fever, vomiting and diarrhea. Persons exposed to fecal coliform can become ill if they have an open cut, wound or scrape that comes into contact with contaminated water. Symptoms include fever, redness and swelling at the site of an open wound. If these symptoms occur, a doctor should be consulted.  

Normally, the Missouri Department of Natural Resources is responsible for water quality testing in the state. However, due to extraordinary circumstances related to responding to the Mississippi River flooding, EPA offered its assistance to the state to conduct this round of limited sampling. The U.S. Geological Survey is also conducting water quality sampling within the floodway.

EPA involvement in the floodway began in mid-April when the agency assisted DNR and bulk fuel suppliers to contact farmers and agricultural operators within the floodway and remove threatened petroleum tanks and small amounts of hazardous materials, prior to the opening of the floodway by the U.S. Army Corps of Engineers.

Source: EPA Region 7 office